The plan is designed to build reservoirs, clean up contaminated groundwater and promote water-treatment technologies, including desalination.

After weeks of difficult negotiations, the ballot measure sailed through both houses of the Legislature: 77-1 in the Assembly and 37-0 in the Senate.

The measure replaces an existing water bond that was approved by a previous Legislature but was widely considered too costly and too bloated with pork-barrel projects to win favor with voters.

The evening legislative votes came after Gov. Jerry Brown and lawmakers from both parties were finally able to clear their main hurdle, a disagreement about how much money should be spent on new reservoirs and other storage projects.